Does immigration add to the economy, providing jobs and growth, or do people arriving in the UK create a financial drain on the country, drawing benefits and taking jobs away from British workers?

The Institute for Public Policy Research (IPPR) says that despite growing concern about Britain's porous borders, immigrants strongly improve the economy.

According to the IPPR, immigrants pay more in tax than the average citizen, contributing £112 in income tax for every £100 paid by a British-born worker. And the total revenue from immigrants is growing faster than tax receipts paid by those born in the UK.

The IPPR report, Paying Their Way, also shows that despite coughing up more, immigrants take rather less, accounting for £7,277 of government spending compared with £7,753 for non-immigrants.

The dynamism injected into the economy by entrepreneurs with origins outside the UK is a crucial part of this story. Many immigrants set up in business so that they can remain independent, avoid racism in the job market and develop security for their family as children and grandchildren are born.

For many, having upped sticks and moved thousands of miles, commitment to the job in hand isn't an issue and ingrained cultural values of hard work often means getting the extended family to pull together in a collective and sustained effort.

It's an approach that is familiar to Lisa Tse, 27, who with her two sisters recently launched Sweet Mandarin, a glamorous cocktail bar and modern Chinese restaurant in Manchester's arty Northern Quarter. She was inspired by her formidable grandmother, Lily Kwok, who made the journey from Hong Kong to Middleton in Lancashire and started a Chinese restaurant in the 50s with her two children, including Lisa's mum Mabel.

"We started helping out there when we very young, so we got used to juggling school with working," Lisa explains. "Managing lots of things has always just been part of our lives."

Lisa feels that being born in the UK allows her to bring the best of both cultures to her business. "An emphasis on service is the Chinese part of how we do things. In the Chinese culture, you don't complain, you just work hard. You're also taught to treat people with kindness and respect. I try to integrate that with Western management techniques where you empower people in their workplace."

Lisa gave up her job in finance to start Sweet Mandarin. She and her sister Janet both cook in the kitchen and she has just returned from a trade mission to China. Just eight months from launch, the sisters have created four full-time jobs and have set up a partnership with the Manchester College of Arts and Technology to offer student placements. They have also instigated heavily discounted meal-deals on Sundays to encourage local people to meet and help create a safer, friendlier neighbourhood.

There is surprisingly little research into the contribution that first, second and third-generation immigrant businesses make to the economy, says Danny Sriskandarajah, who co-wrote the IPPR report. "In the public debate, there are very few good news stories about immigration. It used to be that they were a drain. After the events of July, now it's that they're both a drain and a threat."

This, he says, is in contrast to the approach of Canada, and the countries in Europe which are going out of their way to attract the best and brightest. "This country is years behind. We're missing a trick; we know that entrepreneurs can drive that dynamism, and yet we're driven by a fear of numbers. But if you're adding another person who creates jobs, then you increase the amount of employment."

But, in the north west, which has recognised the need for regeneration after a long period of post-industrial decline, attitudes may be starting to change. The region has historically attracted large numbers of immigrants, and the charity Sustainability Northwest (SNW) has just completed a comparative study of the financial and social contribution of "assimilated entrepreneurs" - people with origins outside the UK.

Their Wealth Bringers report not only finds that businesses run by assimilated entrepreneurs in the northwest have higher turnovers than those run by their counterparts across the UK, but shows that their profits are 13% higher than those generated by an equivalent sample drawn from the region's wider business community.

The value brought by this group of business people is far greater than money though - as Erik Bichard, chief executive of SNW points out. "When we began the study, I was prepared for the negative point of supply chains being focused on people's own communities and the added value thus staying in that community," he says.

"People often accuse minority ethnic populations of being insular and keeping to their own. Nothing could be further from the truth. They take suppliers based on cost and quality, like any other business, so spread the benefits."

He also notes that many of these entrepreneurs participate heavily in community work; some interviewees had become magistrates, chaired local chambers of commerce, founded charities, sponsored major arts group, worked voluntarily with youth groups and supported local schools.

Another approach is to use one's cultural background as a selling point, by setting up a social enterprise catering to the needs of minority ethnic populations. After a conversation with friends from Birmingham's Afro-Caribbean community about the lack of appropriate housing services for black children in care, Roger Telphia, 40, whose parents came from Jamaica, started his not-for-profit business, Health and Future Social Care.

He began by offering supported housing for young people leaving care, and went on to work with people with mental health problems and learning disabilities. Nine years on, with 75 properties under management and a training department that delivered 50 NVQs last year, he provides housing for 300 vulnerable people. Turnover across what has developed into two separate businesses is in excess of £5m and 250 jobs have been created.

Despite his background in financial management however, no bank would offer him a penny in start-up help nine years ago. He had to finance the entire enterprise himself with £20,000 of expensive credit card debt. "If you're an entrepreneur, you make things happen, regardless of the situation you're in."

He worries though that black-led companies can suffer the effects of disproportionate scrutiny, which can affect the willingness of people from minority ethnic communities to stick their necks out in the business world. This has prompted him to go into local schools with high proportions of black and minority ethnic pupils to show them that being an entrepreneur is a viable option for anyone.

Back at Sweet Mandarin, Lisa Tse has taken this lesson on board. She's already looking at franchise options, aware that two to three years ahead, when every hip and trendy business is renting office space in the currently derelict warehouses of Manchester's Northern Quarter, her investment of time, passion and financial risk is likely to pay off big time.